CN111741580B - Device and method for generating high-power wavelength-adjustable extreme ultraviolet light source - Google Patents
Device and method for generating high-power wavelength-adjustable extreme ultraviolet light source Download PDFInfo
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- CN111741580B CN111741580B CN202010712239.7A CN202010712239A CN111741580B CN 111741580 B CN111741580 B CN 111741580B CN 202010712239 A CN202010712239 A CN 202010712239A CN 111741580 B CN111741580 B CN 111741580B
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Abstract
The invention relates to a device and a method for generating a high-power wavelength-adjustable extreme ultraviolet light source, belongs to the technical field of semiconductor photoetching, and solves the problem that the resolution of photoetching is limited because the power and the wavelength of the generated extreme ultraviolet light are not adjustable in the prior art. The device comprises a circular accelerator, a beam splitter and a beam splitter, wherein the circular accelerator is used for accelerating electron beams and enabling the electron beams to do circular motion in the circular accelerator; an optical storage for storing laser pulses; the annular accelerator is communicated with the optical storage, the interiors of the annular accelerator and the optical storage are both vacuum, and the communicated part is a laser electron collision area; in the laser electron collision area, the electron beam collides with the laser pulse to generate scattering action, and extreme ultraviolet light pulse is generated and emitted through the optical memory. The device can generate extreme ultraviolet light by the collision of the electron beam and the laser pulse, and can generate extreme ultraviolet light with different wavelengths and different powers by adjusting the energy of the electron beam and the frequency of the laser pulse.
Description
Technical Field
The invention relates to the technical field of semiconductor photoetching, in particular to a device and a method for generating a high-power wavelength-adjustable extreme ultraviolet light source.
Background
The photolithography using an Extreme Ultraviolet (EUV) light source is the most potential photolithography technique for realizing large-scale industrial and commercial production, the EUV light source realizes smaller node photolithography by greatly reducing the exposure wavelength (by more than one magnitude), and the value of the line width of the primary exposure can reach within 10 nm. The feasibility of 13.5nm EUV light sources in the EUV band has been verified both theoretically and experimentally and has been successfully implemented in existing industrial lithography machines.
In order to realize smaller node photoetching, namely to improve photoetching resolution, obtaining a high-power wavelength-adjustable extreme ultraviolet light source becomes a key technical problem. The prior art generally uses a laser plasma method to generate an euv light source, i.e., a laser is used to heat a working material (such as Xe or Sn) to excite a plasma to radiate euv light. The laser plasma extreme ultraviolet light source is a preferable high-power light source solution for the 13.5nm photoetching technology due to the characteristic of power expansibility. Specifically, a high-power CO2 laser was applied to the tin droplets to generate an EUV light source with a power of 200W and a wavelength of 13.5 nm.
The prior art has at least the following defects that firstly, the laser plasma energy conversion efficiency is limited to be less than 3%, the power is continuously improved and limited, and the large-batch high-efficiency photoetching with the resolution of 5nm or lower is greatly limited; secondly, the wavelength of the generated extreme ultraviolet light source cannot be adjusted due to the characteristic frequency of the radiation of the laser plasma, which is not favorable for further improving the photoetching resolution.
Disclosure of Invention
In view of the foregoing analysis, the present invention aims to provide a device and a method for generating a high-power wavelength-tunable euv light source, so as to solve the problem that the euv light source generated in the prior art has low power and non-tunable wavelength, thereby limiting the resolution of lithography.
In one aspect, the invention provides a device for generating a high-power wavelength-tunable extreme ultraviolet light source, comprising a ring accelerator and an optical memory;
the annular accelerator is used for accelerating the electron beams and enabling the electron beams to do circular motion in the annular accelerator;
the optical storage is used for storing laser pulses;
the annular accelerator is communicated with the optical storage, the interiors of the annular accelerator and the optical storage are both vacuum, and the communicated part is a laser electron collision area;
in the laser electron collision area, the electron beam collides with the laser pulse to generate scattering action, and extreme ultraviolet light pulses are generated and emitted out through the optical memory.
Furthermore, a first opening is formed in the outer ring of the annular accelerator, a second opening matched with the first opening is formed in the optical storage shell, and the first opening is connected with the second opening in a sealing mode;
the distance between the plane where the first opening is located and the annular accelerator inner ring is larger than or equal to 0.
Furthermore, a plurality of reflecting mirrors are arranged on an optical path in the optical storage and are used for enabling the incident laser pulse to circularly propagate in the optical storage;
a reflector which is close to the laser electron collision area and is positioned in front of the laser electron collision area on a light path is a first parabolic reflector and is used for reflecting the laser pulse so that the laser pulse collides with the electron beam in the laser electron collision area;
the first parabolic reflector is arranged at a position which avoids an emergent light path of the generated extreme ultraviolet light pulse; or, an optical aperture is arranged at the center of the first parabolic mirror and used for leading out the generated extreme ultraviolet light pulse.
Furthermore, a reflector which is close to the laser electron collision area and is positioned behind the laser electron collision area on the light path is a second parabolic reflector, and is used for converging the laser pulses emitted from the laser electron collision area into parallel light beams and reflecting the parallel light beams, so that the laser pulses are circularly transmitted in the optical storage.
Further, the size of the light hole is set according to the distance between the focusing center of the first parabolic mirror and the center of the laser electron collision area and the beam divergence angle of the generated extreme ultraviolet light;
wherein r is a radius of the light aperture, L is a distance between a focus center of the first parabolic mirror and a center of the laser electron collision region, and θ is a beam divergence angle of the extreme ultraviolet light.
Furthermore, a third opening is arranged on the shell of the optical storage device, the third opening corresponds to an emergent light path of the extreme ultraviolet light pulse, and the third opening is hermetically connected with the vacuum conduit and used for leading out the extreme ultraviolet light pulse.
Further, the optical storage device further comprises a laser pulse introducer, wherein the laser pulse introducer comprises a Pockels cell and a polarization reflector, and the Pockels cell is positioned on a reflection or transmission light path of the polarization reflector and forms an included angle of 45 degrees with the Pockels cell;
the pockels cell is used for changing the polarization direction of the laser pulse incident through the polarization reflector, and after the laser pulse is incident to the optical storage, the power supply of the pockels cell is controlled to be switched off, so that when the laser pulse is transmitted to the polarization reflector in the optical storage, the laser pulse can be reflected by the polarization reflector to circularly transmit in the optical storage.
Further, a circumference of the optical storage is approximately equal to the laser pulse length.
Furthermore, a section of microwave accelerating tube is arranged in the annular accelerator and used for accelerating the electron beam so that the energy of the electron beam is stabilized at a preset energy value.
In another aspect, the present invention provides a method for generating a high power wavelength tunable euv light source, which utilizes the apparatus for generating a high power wavelength tunable euv light source, the method comprises,
directing laser pulses into the optical storage device, such that the laser pulses circulate in the optical storage device;
injecting the accelerated electron beam into a circular accelerator by using a linear electron accelerator, so that the electron beam makes circular motion in the circular accelerator, the motion direction of the electron beam is opposite to the propagation direction of the laser pulse, and scattering action is generated in a laser electron collision region to generate extreme ultraviolet light pulse, and the extreme ultraviolet light pulse is led out from a vacuum conduit which is connected with a third opening of the optical storage in a sealing way;
wherein, in the laser electron collision region, when the propagation direction of the laser pulse and the movement direction of the electron beam are on the same horizontal line, the wavelength of the generated extreme ultraviolet pulse is determined by the following formula:
wherein λ' represents the wavelength of the laser pulse and γ represents the lorentz factor;
when the propagation direction of the laser pulse is not on the same horizontal line with the movement direction of the electron beam, the wavelength of the generated extreme ultraviolet light pulse is determined by the following formula:
wherein λ' is the wavelength of the laser pulse, α is the angle between the moving direction of the electron beam and the propagation direction of the laser pulse in the laser electron collision region, β is the ratio of the electron velocity to the light velocity in the electron beam, EeIs the energy, ω, of the electrons in said electron beam0H is the Planck constant, which is the frequency of the laser pulses.
Compared with the prior art, the invention can realize at least one of the following beneficial effects:
1. the device and the method for generating the high-power wavelength-adjustable extreme ultraviolet light source provided by the invention abandon the existing method of laser plasma, creatively provide the generation of the extreme ultraviolet light by utilizing the collision of the electron beam and the laser pulse, avoid the defects of low energy conversion efficiency of the laser plasma and limited power of the generated extreme ultraviolet light, improve the utilization rate of the laser pulse and save the cost to a certain extent.
2. According to the device and the method for generating the high-power wavelength-adjustable extreme ultraviolet light source, the wavelength of the generated extreme ultraviolet light can be regulated and controlled by changing the energy of the electron beam and the wavelength and pulse width of the laser pulse, the power of the generated extreme ultraviolet light can be regulated and controlled, and therefore the photoetching resolution is improved.
In the invention, the technical schemes can be combined with each other to realize more preferable combination schemes. Additional features and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and drawings.
Drawings
The drawings are only for purposes of illustrating particular embodiments and are not to be construed as limiting the invention, wherein like reference numerals are used to designate like parts throughout.
FIG. 1 is a schematic diagram of a device for generating a high power wavelength tunable EUV light source in accordance with an embodiment of the present invention;
FIG. 2 is another schematic diagram of a device for generating a high power wavelength tunable EUV light source according to an embodiment of the present invention;
FIG. 3 is a flowchart of a method for generating a high power wavelength tunable EUV light source according to an embodiment of the present invention.
Reference numerals:
1-a linear electron accelerator; 2-a ring accelerator; 3-an optical memory; 4-a polarizing mirror; 5-a first parabolic mirror; 6-a second parabolic mirror; 7-a mirror; 8-pockels cell; 9-laser pulses; 10-an electron beam; 11-pulses of extreme ultraviolet light; 12-light hole.
Detailed Description
The accompanying drawings, which are incorporated in and constitute a part of this application, illustrate preferred embodiments of the invention and together with the description, serve to explain the principles of the invention and not to limit the scope of the invention.
Device embodiment
The invention discloses a device for generating a high-power wavelength-adjustable extreme ultraviolet light source. As shown in fig. 1, the apparatus includes a circular accelerator and an optical storage.
The circular accelerator (2) is used for accelerating the electron beams and enabling the electron beams to do circular motion in the circular accelerator (2).
An optical memory (3) for storing laser pulses. Illustratively, the optical storage may be a cubic shaped cavity of stainless steel.
The annular accelerator (2) is communicated with the optical memory (3), and the communicated part is a laser electron collision area. In order to ensure that the electron movement in the circular accelerator (2) and the laser pulse in the optical storage (3) are not influenced by air, the interiors of the circular accelerator (2) and the optical storage (3) are both vacuum. As shown in fig. 1, illustratively, the circular accelerator (2) is located above the optical storage ring (3), and the lower part of the circular accelerator is communicated with the upper part of the optical storage ring.
In the laser electron collision area, the electron beam collides with the laser pulse to generate scattering action, and extreme ultraviolet light pulse is generated and emitted through the optical memory. Specifically, the length range of the laser electron collision area is 0.5m-1 m.
Preferably, wherein the circular accelerator is offset from the central spatial position of the optical storage by an amount on the order of 1 micron.
Preferably, the outer ring of the annular accelerator (2) is provided with a first opening, the shell of the optical storage (3) is provided with a second opening matched with the first opening, the first opening is connected with the second opening in a sealing mode, and the inner part of the annular accelerator is guaranteed to be in a vacuum state while the annular accelerator is communicated with the second opening.
The distance between the plane of the first opening and the inner ring of the annular accelerator (2) is more than or equal to 0, so that the electron beam and the laser pulse can collide.
Preferably, a plurality of reflecting mirrors are arranged on an optical path in the optical storage (3) and are used for circularly propagating the incident laser pulse in the optical storage and enabling the laser pulse to collide with the electron beam for a plurality of times in a laser electron collision area so as to improve the utilization rate of the laser pulse.
And the reflector which is close to the laser electron collision area and is positioned in front of the laser electron collision area on the light path is a first paraboloid reflector (5) and is used for reflecting the laser pulse so that the laser pulse collides with the electron beam in the laser electron collision area. The parabolic mirror is chosen to focus the laser pulse, increasing its utilization, considering that the laser pulse may be lost after it has been circulated several times in the optical storage.
As shown in fig. 1, the first parabolic mirror (5) is disposed so as to avoid an outgoing optical path of the generated euv light pulse. Alternatively, as shown in fig. 2, an optical aperture (12) is provided at the center of the first parabolic mirror (5) for deriving the generated euv light pulse. Considering that the arrangement of the aperture (12) at the center of the first parabolic mirror (5) may cause a partial laser pulse loss, the energy of the electron beam may be increased to reduce the divergence angle of the euv light pulse generated after the collision between the electron beam and the laser pulse, and at this time, the aperture size may be set small to ensure that the laser pulse loss is not substantially affected during the effective collision time between the electron beam and the laser pulse.
Preferably, the reflector which is close to the laser electron collision area and is positioned behind the laser electron collision area on the optical path is a second parabolic reflector (6) which is used for converging the laser pulses emitted after passing through the laser electron collision area into parallel beams and reflecting the parallel beams, so that the laser pulses are circularly transmitted in the optical storage. Considering that the laser pulse may be dispersed after colliding with the electron beam, the parabolic reflector converges the dispersed laser pulse to improve the utilization rate of the laser pulse.
Specifically, the size of the light hole (12) is set according to the distance between the focusing center of the first parabolic mirror (5) and the center of the laser electron collision area and the beam divergence angle of the generated extreme ultraviolet light;
wherein r is the radius of the light hole (12), L is the distance between the focusing center of the first parabolic reflector (5) and the center of the laser electron collision area, and theta is the beam divergence angle of the extreme ultraviolet light.
Specifically, the beam spread angle of the extreme ultraviolet light is obtained by the following formula:
wherein, veIs the kinetic energy of the electron beam and c is the speed of light.
After the electron beam has moved for a while in the circular accelerator (2), energy is lost. Therefore, a section of microwave accelerating tube is arranged in the annular accelerator (2) and used for accelerating the electron beam to supplement energy so as to stabilize the energy of the electron beam at a preset energy value. On one hand, the power of the generated extreme ultraviolet light pulse can be ensured to be unchanged, and on the other hand, the beam divergence angle of the extreme ultraviolet light can be ensured not to be increased, so that the emergent of the generated extreme ultraviolet light can not be blocked by the preset light hole (12) or the preset position of the first parabolic reflector (5). Specifically, the microwave accelerating tube may be disposed at a position other than the laser electron collision region.
Preferably, a third opening is provided in the housing of the optical storage (3), the third opening corresponding to an emission path of the generated euv light pulse, and the third opening being in sealed contact with the vacuum conduit for deriving the generated euv light pulse. Illustratively, the generated euv light pulses are directed out through a vacuum conduit to a location of use, depending on the requirements of the use.
Preferably, the optical storage (3) further comprises a laser pulse introducer comprising a pockels cell (8) and a polarizing mirror (4), the pockels cell (8) being located on a reflected or transmitted light path of the polarizing mirror (4) and being at an angle of 45 ° to the pockels cell (8).
Illustratively, laser pulses are incident on a polarization mirror (4), the laser pulses are transmitted through the polarization mirror (4) and incident on a Pockels cell (8), the Pockels cell (8) can change the polarization direction of the laser pulses, and then the Pockels cell (8) is controlled to be powered off. When the laser pulse circularly propagates in the optical memory (3) and enters the polarization reflector (4), the polarization direction of the laser pulse is changed, so that the laser pulse can be reflected by the polarization reflector (4) and can not be transmitted through the polarization reflector (4), after the laser pulse passes through the Pockels cell (8), the Pockels cell (8) does not act on the laser pulse, and the laser pulse can be circularly propagated in the optical memory (3) to be stored in the optical memory (3).
Preferably, the circumference of the optical memory (3) is approximately equal to the laser pulse length. Specifically, the length of a laser pulse refers to the product of the pulse width (i.e., the pulse duration) and the propagation speed of the laser pulse.
Method embodiment
The invention further discloses a method for generating the high-power wavelength-adjustable extreme ultraviolet light source, which utilizes the device for generating the high-power wavelength-adjustable extreme ultraviolet light source. As shown in fig. 3, the method includes:
the laser pulses are guided into the optical storage (3) and are circulated in the optical storage (3).
The accelerated electron beam is injected into the annular accelerator (2) by using the linear electron accelerator (1) to make the electron beam do circular motion in the annular accelerator (2), the motion direction of the electron beam is opposite to the propagation direction of the laser pulse, and the electron beam generates scattering action in a laser electron collision region to generate extreme ultraviolet light pulse and is led out from a vacuum conduit which is connected with a third opening of the optical storage (3) in a sealing way.
In the laser electron collision area, when the propagation direction of the laser pulse and the movement direction of the electron beam are on the same horizontal line, at this time, a light hole is arranged at the center of the first parabolic reflector, and the wavelength of the generated extreme ultraviolet pulse is determined by the following formula:
where λ' represents the wavelength of the laser pulse and γ represents the lorentz factor.
When the propagation direction of the laser pulse is not on the same horizontal line with the movement direction of the electron beam, at this time, the setting position of the first parabolic mirror avoids the emergent light path of the generated extreme ultraviolet light pulse, and the wavelength of the generated extreme ultraviolet light pulse is determined by the following formula:
wherein λ' is the wavelength of the laser pulse, α is the angle between the moving direction of the electron beam and the propagation direction of the laser pulse in the laser electron collision region, β is the ratio of the electron velocity to the light velocity in the electron beam, EeIs the energy, ω, of the electrons in said electron beam0H is the Planck constant, which is the frequency of the laser pulses.
The advantageous effects of the present invention are now demonstrated by the following specific examples.
Illustratively, the circular accelerator has a radius of 1 m.
The energy of the electron beam is selected to be in the range of 7.16MeV-14.32MeV, the pulse width of the electron beam is selected to be in the range of 1-10ps, the charge amount of a single electron beam pulse is 1-2nC, the electron beam is rotated for a circle in the circular accelerator for 21ns, the electron beam pulses are injected at equal intervals, and the time interval between the electron beam pulses is about 100 ps.
Laser pulses of CO2Laser pulses with a pulse width of 40ns and a frequency of 50kHz, with a single laser pulse energy of 10J.
After being accelerated by a linear electron accelerator with low energy of 7.16MeV-14.32MeV, the electron beam is injected into a circular accelerator, the electron beam rotates in the circular accelerator at a fixed speed, and the generated synchrotron radiation is in a visible light wave band and does not influence the energy of the electron beam and the generated extreme ultraviolet light pulse. The electron ring is provided with a section of microwave accelerating tube which can supplement energy for the electron beam losing energy, so that the energy of the electron beam is always kept at a set energy value.
At the same time, CO is introduced by means of a laser pulse introducer2The laser pulses are introduced into the optical storage device and are caused to circulate in the optical storage device. When the electron beam moves to the laser electron collision area and CO2The laser pulse generates collision (namely, generates inverse Compton scattering effect), and then the quasi-unienergy extreme ultraviolet light pulse can be generated.
Specifically, 210 electron beam pulses are injected at equal time intervals, and then CO is injected2During the laser pulse interaction, there will be 400 electron beam pulses with CO2The laser pulses collide to generate extreme ultraviolet light pulses. Due to the perimeter of the optical storage and a CO2Laser pulse lengths are approximately equal so that the CO2The laser pulse is just captured in the optical storage ring, can repeatedly collide with the electron beam for multiple times and continuously generate extreme ultraviolet light, so that the yield of the extreme ultraviolet light is improved.
Theoretically CO2The laser pulses can be circulated an unlimited number of times in the optical storage. But there will actually be CO2Laser pulse loss, if the reflectivity is 99.99%, can be calculated as the CO after 4000 reflections2The laser pulse is transferred 500 turns in the storage ring and the laser pulse energy remains around 80%. Thus, at least 500 times of amplification of the euv light pulse, i.e. 500 times of the duration of the euv light pulse, can be achieved.
When in the laser electron collision region, the moving direction of the electron beam and the CO2When the propagation directions of the laser pulses are not on the same horizontal line, the collision angle is exemplarily
The wavelength of the generated extreme ultraviolet light pulse is as follows:
wherein λ' is CO2The wavelength of the laser pulse, alpha is the included angle between the moving direction of the electron beam in the laser electron clash area and the propagation direction of the laser pulse, beta is the ratio of the electron speed to the light speed in the electron beam, EeIs the energy, ω, of the electrons in the electron beam0H is the Planck constant, the frequency of the laser pulses.
Specifically, CO can be changed based on the included collision angle alpha2The wavelength of the laser pulse or the energy of the electron beam regulates and controls the wavelength of the extreme ultraviolet light pulse.
When in the laser electron collision region, the moving direction of the electron beam and the CO2When the propagation directions of the laser pulses are on the same horizontal line, the wavelengths of the generated ultraviolet light are as follows:
where λ' represents the wavelength of the laser pulse and γ represents the lorentz factor.
Thus, CO2The laser pulse collides with the electron beam to generate the extreme ultraviolet light adjustable in the range of 13.5nm-3.375nm, when the energy of the electron beam is 7.16MeV, the extreme ultraviolet light pulse with the wavelength of 13.5nm can be generated, and when the energy of the electron beam is 14.32MeV, the extreme ultraviolet light pulse with the wavelength of 3.375nm can be generated.
The laser wavelength and the electron beam energy can be specifically selected in the following manner.
As can be seen from equation (2), the wavelength of the generated euv light is proportional to the laser wavelength and inversely proportional to the square of the electron beam energy. In order to ensure the stability of the circular accelerator, the energy of the electron beam is selected to be about 10MeV or more as much as possible, and in addition, the energy of the electron beam is not too high easily in order to reduce the complexity of the circular accelerator and improve the reliability of the circular accelerator. Illustratively, the electron beam energy is 10MeV, the laser pulse wavelength is 10.6 microns, and the extreme ultraviolet light generated during collision has a wavelength of 7 nm. Correspondingly, if a high-energy electron beam is to be selected, a laser pulse of a longer wavelength is required, and if the electron energy is increased by 5 times, the laser wavelength must be increased by 25 times, and then the laser enters the mm band, i.e., a high-frequency wave of 300 GHz.
For both cases, single CO2The power of the extreme ultraviolet light pulse generated by the laser pulse is as follows:
Δ beam represents the time interval between beam pulses, i.e. a CO in the laser electron collision region2In the time of laser pulse, with CO2The number of beam pulses of the laser pulse collision is equal to CO2Laser pulse time divided by the time interval of the electron beam pulses, Ne representing the number of electrons in a single electron beam pulse, τLDenotes the pulse width, IP, of the CO2 laser pulselengthRepresents CO2Length of laser electron collision zone. SigmatotalRepresents CO2The total cross section of the laser pulse scattering from the collision with the electron beam is about 200mbar omegaEUVRepresenting the angular frequency of the extreme ultraviolet light, r representing CO2The focal spot radius of the laser pulse,
represents a single CO2The energy of the laser pulse, e, is the unit cell charge.
Specifically, the angular frequency of the extreme ultraviolet light is obtained by the following formula:
where λ is the wavelength of the generated euv light pulse and c is the speed of light.
CO is obtained by the following formula2Total cross section of laser pulse and electron beam collision scattering:
wherein epsilon0Is a vacuum dielectric constant, meIs an electron static mass reIs a classical electron radius.
In particular, the power of the EUV light pulse and CO2The energy of the laser pulse is proportional to the charge of the electron beam pulse, and therefore the CO can be changed2The power of the extreme ultraviolet light is regulated and controlled by the energy of the laser pulse or the charge quantity of the electron beam pulse, and the maximum power of the extreme ultraviolet light can reach 500W at present.
Compared with the prior art, the device and the method for generating the high-power wavelength-adjustable extreme ultraviolet light source provided by the invention firstly abandon the existing laser plasma method, creatively provide the extreme ultraviolet light generated by colliding the electron beam with the laser pulse, avoid the defects of low energy conversion efficiency of the laser plasma and limited power of the generated extreme ultraviolet light, improve the utilization rate of the laser pulse and save the cost to a certain extent; the device and the method for generating the high-power wavelength-adjustable extreme ultraviolet light source provided by the invention can realize the regulation and control of the wavelength of the generated extreme ultraviolet light and the regulation and control of the power of the generated extreme ultraviolet light by changing the energy of the electron beam, the wavelength and the pulse width of the laser pulse, thereby improving the photoetching resolution.
The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention are included in the scope of the present invention.
Claims (10)
1. A generation device of a high-power wavelength-adjustable extreme ultraviolet light source is characterized by comprising a ring-shaped accelerator and an optical memory;
the annular accelerator is used for accelerating the electron beams and enabling the electron beams to do circular motion in the annular accelerator;
the optical storage is used for storing laser pulses;
the annular accelerator is communicated with the optical storage, the interiors of the annular accelerator and the optical storage are both vacuum, and the communicated part is a laser electron collision area;
in the laser electron collision area, the electron beam collides with the laser pulse to generate scattering action, and extreme ultraviolet light pulses are generated and emitted out through the optical memory.
2. The euv light source generating device according to claim 1, wherein the outer ring of the ring accelerator has a first opening, the optical storage enclosure has a second opening matching with the first opening, and the first opening and the second opening are in sealing connection;
the distance between the plane where the first opening is located and the annular accelerator inner ring is larger than or equal to 0.
3. The euv light source generating device according to claim 1 or 2, wherein a plurality of mirrors are arranged on the optical path in the optical storage for circulating the incident laser light pulses in the optical storage;
a reflector which is close to the laser electron collision area and is positioned in front of the laser electron collision area on a light path is a first paraboloid reflector and is used for reflecting the laser pulse so that the laser pulse collides with the electron beam in the laser electron collision area;
the setting position of the first parabolic reflector avoids an emergent light path of the extreme ultraviolet light pulse; or, a light hole is arranged at the center of the first parabolic reflector and used for guiding out the generated extreme ultraviolet light pulse.
4. The euv light source generating device according to claim 3, wherein the reflector adjacent to and optically behind the laser electron collision region is a second parabolic reflector, and is configured to converge and reflect the laser pulses emitted from the laser electron collision region into parallel beams, so that the laser pulses are circularly propagated in the optical storage.
5. The euv light source generation apparatus of claim 3, wherein the size of the light aperture is set according to the distance between the focus center of the first parabolic reflector and the center of the laser electron collision region and the beam divergence angle of the generated euv light;
wherein r is the radius of the light hole, L is the distance between the focus center of the first parabolic reflector and the center of the laser electron collision region, and θ is the beam divergence angle of the extreme ultraviolet light.
6. The generating device of the extreme ultraviolet light source as claimed in claim 3, wherein a third opening is provided on the housing of the optical storage, the third opening corresponds to an exit path of the generated extreme ultraviolet light pulse, and the third opening is hermetically connected to a vacuum conduit for leading out the generated extreme ultraviolet light pulse.
7. The generation apparatus of the euv light source according to any one of claims 1, 2, 4-6, wherein the optical storage further comprises a laser pulse introducer, the laser pulse introducer comprising a pockels cell and a polarizing mirror, the pockels cell being located on a reflected or transmitted light path of the polarizing mirror and being at an angle of 45 ° with respect to the pockels cell;
the pockels cell is used for changing the polarization direction of the laser pulse incident through the polarization reflector, and after the laser pulse is incident to the optical storage, the power supply of the pockels cell is controlled to be switched off, so that when the laser pulse is transmitted to the polarization reflector in the optical storage, the laser pulse can be reflected by the polarization reflector to circularly transmit in the optical storage.
8. The apparatus of claim 7, wherein the optical storage has a perimeter approximately equal to the laser pulse length.
9. The euv light source generating apparatus as claimed in claim 7, wherein a section of the microwave accelerating tube is disposed in the circular accelerator for accelerating the electron beam so that the energy of the electron beam is stabilized at a predetermined energy value.
10. A method for generating a high-power wavelength-tunable extreme ultraviolet light source by using the device for generating a high-power wavelength-tunable extreme ultraviolet light source as claimed in any one of claims 1 to 9, comprising,
directing laser pulses into the optical storage device, such that the laser pulses circulate in the optical storage device;
injecting the accelerated electron beam into a circular accelerator by using a linear electron accelerator, so that the electron beam makes circular motion in the circular accelerator, the motion direction of the electron beam is opposite to the propagation direction of the laser pulse, and scattering action is generated in a laser electron collision region to generate extreme ultraviolet light pulse, and the extreme ultraviolet light pulse is led out from a vacuum conduit which is connected with a third opening of the optical storage in a sealing way;
wherein, in the laser electron collision region, when the propagation direction of the laser pulse and the movement direction of the electron beam are on the same horizontal line, the wavelength of the generated extreme ultraviolet light pulse is determined by the following formula:
wherein λ' represents the wavelength of the laser pulse and γ represents the lorentz factor;
when the propagation direction of the laser pulse is not on the same horizontal line with the movement direction of the electron beam, the wavelength of the generated extreme ultraviolet light pulse is determined by the following formula:
wherein λ' is the wavelength of the laser pulse, α is the angle between the moving direction of the electron beam and the propagation direction of the laser pulse in the laser electron collision region, β is the ratio of the electron velocity to the light velocity in the electron beam, EeIs the energy, ω, of the electrons in said electron beam0H is the Planck constant, which is the frequency of the laser pulses.
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| CN102231935A (en) * | 2011-05-31 | 2011-11-02 | 长春理工大学 | Method and apparatus for generating coherent extreme ultraviolet radiation |
| CN110383175A (en) * | 2017-04-26 | 2019-10-25 | 极光先进雷射株式会社 | EUV photogenerated device |
| CN110944439A (en) * | 2019-10-29 | 2020-03-31 | 清华大学 | High average power extreme ultraviolet light source device based on electronic storage ring |
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| CN102231935A (en) * | 2011-05-31 | 2011-11-02 | 长春理工大学 | Method and apparatus for generating coherent extreme ultraviolet radiation |
| CN110383175A (en) * | 2017-04-26 | 2019-10-25 | 极光先进雷射株式会社 | EUV photogenerated device |
| CN110944439A (en) * | 2019-10-29 | 2020-03-31 | 清华大学 | High average power extreme ultraviolet light source device based on electronic storage ring |
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